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Ammonia-borane (AB) is one of the most promising fuel forms for the hydrogen economy, but the reaction requires a good catalyst to accelerate this hydrolysis reaction under ambient conditions. Here, H2 evolution upon hydrolysis of ammonia-borane catalyzed by tetra-(p-hydroxyphenyl) porphyrin (THPP) stabilized transition metal nanoparticles (RhNPs/THPP, RuNPs/THPP, PtNPs/THPP) has been reported for the first time. The as-synthesized nanocomposites (TMNPs/THPP) show high catalytic activity in the AB hydrolysis. Among these TMNPs/THPP, the RhNP-3/THPP exhibits the best catalytic activity with a TOF of 213.64 molH2 molcata−1 min−1. In addition, tandem reaction for 1,1-diphenylethylene hydrogenation has also confirmed the H2 evolution upon hydrolysis of ammonia-borane.

Seven-membered N, O-ligands containing ketone and pyrrole have been designed and synthesized via a facile method using organocatalyst, piperidinium acetate or L-proline. Their photophysical properties including absorption and emission spectra have been investigated in eight kinds of different polar solvents. DFT and TD-DFT calculations have also been carried out to further demonstrate the geometric structures and illuminate their extraordinary photochemical properties. The calculations show that ESIPT process is prohibited in both compounds NOAB-1, 2 which is confirmed by experiment and calculation due to its stable ketone structure.

The one-flask synthesis of seven-membered free-base BOPYINs (NBs) using benzo indole and β-substituted pyrrole moieties has been reported. This stable cis-configuration of diarylethenes with Aggregation Induced Emission (AIE) properties was locked by the seven-membered ring hydrogen bond (HB) and steric hindrance, which made 'Excited-State Intramolecular Proton Transfer (ESIPT)' phenomena take place in this benchmark.

A series of new 3H-Pyrrolizine fused ‘naked’ diazaborepin (NDABs) have been strategically designed and synthesized by replacing one of the hydrogens on pyrrole and/or indole units with electron-donating/withdrawing groups. NDABs contain a seven-membered N-H···N (H-bond) between proton donor (pyrrole) and proton acceptor (indole) moieties. The structures are characterized by 1H NMR, 13C NMR, and high-resolution mass spectrum (HR-MS). Photophysical properties are discussed by the absorption and emission spectra, DFT calculation. NDABs show characteristic strong absorption bands with high molar absorption coefficients, and emission bands with high quantum yields (0.14–0.47) and large Stokes shifts (7270-8025 cm−1). Based on this benchmark, ESIPT process was studied by electronic spectra, geometry, dynamics and thermodynamics analysis. The results demonstrate that the different substitutions at various positions of parent molecule, altered the strength of intramolecular H-bond, tuned the speed of ESIPT process which is consistent with the experimentally observed. On this -NH- type system, ESIPT process has been dramatically affected by the substitution on proton donor moiety and slightly on the proton acceptor moiety.

A speed tunable excited-state intramolecular proton transfer (ESIPT) system featuring a seven-membered ring, -NH- type hydrogen bonding pyrrole-indole moiety based on ‘naked’ diazaborepins (NDABs) was exhibited. In this paper, the speed of ESIPT process can be tuned by the substituents on indole ring, including electron donating and withdrawing group for NDAB-H, NDAB-OMe, NDAB-COOEt, NDAB-NEt2, NDAB-CF3. It has explained by DFT and TD-DFT calculation in nonpolar toluene. The energy gaps between N S1 and T S1 (△E = ET-S1 − EN-S1) of most NDABs are slightly positive, except for the energy gap of NDAB-NEt2 with strong donating group on indole ring is negative. Meanwhile, the S1 state potential energy curve of NDABs with a small energy barrier is in the order NDAB-NEt2